Needle bed racking mechanism in a flat knitting machine

ABSTRACT

A racking cam for producing needle bed shogging steps of respectively different extents in a flat knitting machine. A racking cam carrier carries about its periphery a racking cam having a plurality of shogging positions. Each shogging position includes a device for varying the form of the cam at that position. The device may include a block on the periphery of the racking cam carrier and forming a part of the racking cam at each shogging position. This block may be mounted by a connecting structure including an eccentric element such that movement of this eccentric element moves the block in a direction generally parallel to the axis of rotation of the racking cam carrier.

United States Patent [1 1 Hadam et al.

[ NEEDLE BED RACKING MECHANISM IN A FLAT KNITTING MACHINE [75]Inventors: Wilhelm Hadam; Adam Miiller,

both of Reutlingen, Germany [7 3] Assignee: H. Stoll and Company,Stollweg,

Germany [22] Filed: Jan. 20, 1972 [21] Appl. No.: 219,483

[30] Foreign Application Priority Data 943,921 12/1909 Dubied et a].66/69 [451 July 31,1973

' FOREIGN PATENTS 0R Al PLICATI ONS 217,147 2/1942 Switzerland 66/69Primary Examiner-Ronald Feldbaum z trb friey iloberts B. Larson/MarvinPetry et al.

[5 7] ABSTRACT A racking cam for producing needle bed shogging steps ofrespectively different extents in a flat knitting machine. A racking camcarrier carries about its periphery a racking carn having a plurality ofshogging positions. Each shogging position includes a device for varyingthe form of the cam at that position. The device may include a block onthe periphery of the racking cam carrier and forming a part of theracking cam at each shogging position. This block may be mounted by aconnecting structure including an eccentric element such that movementof this eccentric element moves the block in a direction generallyparallel to the axis of rotation of the racking cam carrier.

i0 Claim, t timing Figures NEEDLE BED RACKING MECHANISM IN A FLATKNITTHNG MACHINE The type of knitting machine to which this inventionrelates, and the general relationship of a racking cam thereto is shownin U.S. Pat. No. 1,992,982, the disclosure of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION This invention relates to a needle bedracking, i.e. shogging, mechanism in a flat knitting machine equippedwith a racking cam for producing needle bed shogging steps ofrespectively different extents.

In the production of rack stitch patterns on automatic flat knittingmachines, particularly those having jacquard patterning arrangements, anoblique pull is exerted on the needles by the racking or shogging of theneedle beds and this may result in lateral bending of the resilientneedles out of their normal plane of movement. Bending of the needles inthis way jeopardizes positive cooperation between the needles whichtransfer and the needles which receive stitches or the co-action betweenthe needles and the transfer jacks during stitch transferringoperations. It would, therefore, be of advantage if the magnitude of theshogs in the racking steps could be adjustable to the extent of a fewtenths of a millimeter to take into account the lateral bending of theneedles caused by the oblique pull on the stitches.

Shogs of the needle bed to required extents, for example over one to sixneedles, are usually effected with the assistance of continuouslyrotating cam tracks which, for instance, are either formed on theracking carriage by an oblique straight edge or defined by a helicalline on a rotatable racking cam carrier. The shogging strokes in suchprior mechanisms could be corrected by a variation in the amount ofmovement of the racking carriage or degree of movement of the rotatingcam carrier per shog, for example by driving the carriage or the rotarycam by stepped motors at an appropriate stepdown ratio, or by varyingthe gradient of the racking cam. Both these possibilities of adjustmentcan, however, only be carried out with great difficulty, and experiencehas shown that the problem cannot be solved by correction of the partialshogs which are proportional to the overall shogging stroke of themechanism, but that differing correction values must be applied to theindividual shogs.

SUMMARY OF THE INVENTION Thus, it is a purpose of this invention toprovide a new and improved arrangement in racking cams for flat knittingmachines which will facilitate the task of providing shogging steps ofrespectively different extents.

It is a further purpose of the present invention to provide a needle bedracking mechanism for a flat knitting machien which, while overcomingthe aforementioned difficulties, will allow in respect of each shogproduced by a racking step for a desired degree of shogging to be setwithin a range of correction, and for this value to be chosenindividually for each step independently of the values chosen for theother steps.

This purpose is achieved according to the present invention by the factthat the racking cam carrier has mounted therein, at each shogging stepposition of the Each control means may be in the form of a block whichis inserted into and is movable relatively to the cam carrier foradjustment through the medium of an eccentric. These eccentricstherefore allow for infinitely variable adjustments of the controlblocks.

In a preferred constructional embodiment of the invention, the controlblocks are of the same width as a part of the racking cam carrierconstituting the actual racking cam, each such block being formed with agroove which extends parallel to the edges of the racking cam andtransversely with respect to the direction of shogging of the needle bedand accomodating a bored block member having a hole serving to locate,with a close working fit, an eccentric flange on a central boss which isarranged for turning movement adjustably within the racking cam carrierand is adapted to be secured in position, after an adjustment, by meansof a tighting screw.

Advantageously, the eccentric flange of each central boss has atransverse slot in which a screwdriver can be inserted, and thecorresponding bored block is provided around the edge of the holetherein with an annular scale designed to indicate the degree ofadjustment of the boss.

The invention can be used with any type of racking cam carrier, that isto say both a known form of racking straight edge or a known form ofrotary racking body. A control block is provided for each needle bedshogging position of the racking cam and this block can be set to arequired corrected shogging position independently of the other controlblocks and will determine the exact degree of shogging of the needle bedfor the racking steps concerned.

Thus, it is a purpose of this invention to provide, in a flat knittingmachine, a new and improved racking cam for producing needle bedshogging steps by difiering amounts.

It is another object of this invention to provide, in a flat bedknitting machine, a new and improved racking cam having means at eachshogging position for changing the form of the cam thereat to produceshogging of differing amounts at different shogging positions, theadjustment at each shogging position being independent of theadjustments at the other shogging positions.

It is another object of this invention to provide, in a flat bedknitting machine, a racking cam having a block at each shogging positionthereof, the sides of the block forming the racking cam at thatposition, each block being connected to the racking cam carrier byconnecting means including an eccentric element, the turning of whicheccentric element adjusts the block to determine the extent of shoggingat that position.

It is another object of this invention to provide a new and improvedracking cam for use in a flat knitting machine comprising means at eachshogging position thereof for changing the extent of shogging thereatindependently of the extent of shogging at other shogging positions ofthe racking cam.

It is another object of this invention to provide a racking cam for aflat knitting machine including blocks located at various shoggingpositions of the racking cam, each block being connected to the rackingcam carrier by means including an eccentric element, the turning ofwhich element adjusts the position of the block.

Other objects and advantages of the invention will become apparent fromthe detailed description to follow, together with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS There follows a detailed descriptionof one preferred embodiment of the invention which is to be readtogether with the accompanying drawings.

FIG. 1 is an elevational view, as seen in the axial direction, of arotatable type racking cam constructed to include the features of thepresent invention.

FIG. 2 is a sectional view taken along line 11-11 of FIG. 1.

FIG. 3 is a partial development of the racking cam of FIG. 1 on theracking cam carrier, this development spanning three successive rackingsteps.

FIG. 4 is a detailed sectional view taken along the line IVIV of FIG. 3and drawn on an enlarged scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring now the drawings, like elements are represented by likenumerals throughout the several views. As noted earlier, the features ofthe present invention may be applied either to an oblique straight edgecam or a cam defined by a helical line on a rotatable racking camsurface. For simplicity, however, the invention will be described indetail only with respect to the latter.

In the drawings is shown a racking cam carrier which is in the form of arotatable body known per se. This carrier has a racking cam constitutedby a helically-extending edge 12 of a flange 11 on a cam plate 100. Theracking cam carrier 10 is mounted on a shaft 30 which extends parallelto the needle bed and constitutes a part of the racking assembly of themachine operable at the dictates of a control mechanism.

The flange ll of the cam plate 10a of carrier 10 is provided in andaround its periphery with regularly spaced transverse grooves 13 whichextend parallel to the direction of racking of the needle bed andcorrespond in each case to the racking of the needle bed to the extentof one needle. A control block 14 is fitted accurately into each ofthese transverse grooves 13, each such block being of the same width asthe flange 11 and having the same gradient, i.e. angle of obliquity, asthe latter relative to the direction of racking. These blocks 14 areeach provided with a transverse groove 15 extending parallel to thehelical edges 12 of flange 11. Where there are severe inclinations inthe racking curve represented by the edges 12 the grooves 15 in theblocks 14 may even be disposed transversely with respect to the rotaryaxis a of the carrier 10.

Fitted into the transverse groove 15 of each control blcok l4 is acounter-bored block member 16 having therein a circular hole I6 toaccomodate, with a close working fit, an eccentric flange 17 on acentral boss 18. This boss 18 is mounted within a hole 19 in the camplate 10a which latter is formed integrally with the racking cam carrier10. The inner end of the mounting hole 19 terminates in a co-axialthreaded bore 20 in the cam plate 10a, and a tightening screw 21concentric with the central boss 18 is screwed into the said bore 20.

The eccentric flange 17 of boss 18 has formed therein a transverse slot22 for the insertion of the bit of a screwdriver, and a scale 23, ismarked on the block member 16 around the edge of the hole 16' thereinaccomodating the said flange.

When any one of the tightening screws 21 is un locked, the correspondingboss 18 can be turned by a screwdriver inserted into the slot 22. Bythis means the relevant bored block member 16, together with the block14 into which it is fitted, can be shifted in one or other directionparallel both to the direction of racking of the needle bed and also tothe rotational axis a of the cam carrier 10 so that such block 14 willproject over one or other of the two edges 12 of the flange ll.Positioning of the slot 22 relatively to the scale marking 23 on blockmember 16 enables the degree of adjustment of the corresponding controlblock 14 to be determined and controlled. This shifting of a controlblock 14 varies the extent of the shog in a racking stage of the needlebed which is determined by the position of the racking cam on which thesaid block is located. This enables the differing values to be given tothe racking stage shogs for the differing shogging stages, one of thecontrol blocks 14 being associated with each such stage.

In the application of the present invention to a straight edge rackingcam, such a cam might appear in plan view just like the development viewof FIG. 3 herein, the straight edges being arranged obliquely relativeto the direction of racking which would be parallel to the line in FIG.3, the block 14 and their associated and connecting adjusting elementsbeing arranged along the length of the straight edge cam.

Although the invention has been described in considerable detail withrespect to preferred embodiments thereof, it will be apparent that theinvention is capable of numerous modifications and variations apparentto those skilled in the art without departing from the spirit and scopeof the invention.

We claim:

1. A flat knitting machine having a racking cam means for producingneedle bed shogging steps comprising, a racking cam carrier, a rackingcam mounted on the racking cam carrier and extending in a generallyoblique direction relative to the direction of racking, the racking camincluding a plurality of shogging step positions spaced therealong, andcontrol means for varying the extent of shogging at each shogging stepposition of the racking cam means said control means comprising theconstruction in which said cam includes a block at each shagging stepposition, the surface of the block forming the form of the cam at thatshogging step position, each block being adjustable relative to theracking cam carrier and independently of the blocks at the othershogging step positions in a direction generally parallel to thedirection of racking of the racking cam carrier.

2. The invention of claim 1, each block being mounted on the racking camcarrier by connecting means which includes an eccentric element, theturning of which element adjusts that block in said direction.

3. The invention of claim 2, wherein the blocks are of the same width,taken in the said direction of racking, each such block being formedwith a groove which extends parallel to the edges of the racking cam andtransversely with respect to the direction of shagging of the needle, abored member accomodated in said groove and including a hole passingtherethrough which locates, with a close working fit, an eccentricflange on a central boss, said eccentric flange constituting the saideccentric element and being arranged for turning movement adjustablywithin the racking cam carrier to move the bored member and hence theblock in said direction to adjust the block.

4. The invention of claim 3, including a screw passing through theeccentric flange and central boss and threadedly engaged in a rackingcam plate which is fixed with respect to the racking cam carrier suchthat when screwed into the racking cam plate it secures in place theeccentric flange and central boss and hence also the bored member andthe said block.

5. The invention according to claim 4, wherein each eccentric flange hasa transverse slot adapted to receive a screwdriver or the like forturning it, and its corresponding bored member is provided around theedge of the hole therein with an annular scale designed to indicate thedegree of adjustment of the eccentric flange and hence also the degreeof adjustment of the block.

6. The invention of claim 1, wherein said racking cam carrier is mountedfor rotation about an axis and the racking cam is located on theperiphery thereof and extends in a helical path thereabout, the axis ofrotation of said racking cam carrier and said racking cam being parallelto the said direction of racking.

7. A racking cam mechanism for use in a flat knitting machinecomprising: a racking cam carrier having a racking cam mounted thereonand extending in an oblique direction relative to the direction ofracking, said racking cam including a plurality of discrete oppositeshogging positions spaced therealong, the racking cam, at each of saidpositions, including a control means for varying the form of the camthereat independently of the form of the cam at the other shoggingposition.

8. A racking cam mechanism according to claim 7, said control meanscomprising the construction in which said cam includes a block at eachshogging position, the surface of the block forming the form of a cam atthat position, each block being adjustable relative to the racking camcarrier in a direction generally parallel to the direction of racking ofthe racking cam carrier, each block being the same width, taken in saiddirection of racking, as the racking cam, each such block being formedwith a groove which extends parallel to the edge of the racking cam, abored member accom' modated in said groove and including a hole passingtherethrough which locates, with a close working fit, an eccentricflange on a central boss, said eccentric flange being arranged forturning movement adjustably within the racking cam carrier to move thebored member and hence the block in said direction of racking to adjustthe block.

9. A racking cam mechanism according to claim 8, including a screwpassing through the eccentric flange and central boss and threadedlyengaged with respect to the racking cani carrier such that when screwedinwardly with respect to the racking cam carrier it secures in place theeccentric flange and central boss and, hence also the bored member andthe said block, each eccentric flange having a transverse slot adaptedto receive a screwdriver of the like for turning it, and itscorresponding bored member being provided around the edge of the holetherein with an annular scale designed to indicate the degree ofadjustment of the eccentric flange, and hence also the degree ofadjustment of the block.

10. The invention of claim 7, wherein said racking cam carrier ismounted for rotation about an axis and the racking cam is located on theperiphery thereof, and extends in a helical path thereabout, the axis ofrotation of said racking cam carrier and said racking cam being parallelto the said direction of racking;

1. A flat knitting machine having a racking cam means for producingneedle bed shogging steps comprising, a racking cam carrier, a rackingcam mounted on the racking cam carrier and extending in a generallyoblique direction relative to the direction of racking, the racking camincluding a plurality of shogging step positions spaced therealong, andcontrol means for varying the extent of shogging at each shogging stepposition of the racking cam means said control means comprising theconstruction in which said cam includes a block at each shogging stepposition, the surface of the block forming the form of the cam at thatshogging step position, each block being adjustable relative to theracking cam carrier and independently of the blocks at the othershogging step positions in a direction generally parallel to thedirection of racking of the racking cam carrier.
 2. The invention ofclaim 1, each block being mounted on the racking cam carrier byconnecting means which includes an eccentric element, the turning ofwhich element adjusts that block in said direction.
 3. The invention ofclaim 2, wherein the blocks are of the same width, taken in the saiddirection of racking, each such block being formed with a groove whichextends parallel to the edges of the racking cam and transversely withrespect to the direction of shogging of the needle, a bored memberaccomodated in said groove and including a hole passing therethroughwhich locates, with a close working fit, an eccentric flange on acentral boss, said eccentric flange constituting the said eccentricelement and being arranged for turning movement adjustably within theracking cam carrier to move the bored member and hence the block in saiddirection to adjust the block.
 4. The invention of claim 3, including ascrew passing through the eccentric flange and central boss andthreadedly engaged in a racking cam plate which is fixed with respect tothe racking cam carrier such that when screwed into the racking camplate it secures in place the eccentric flange and central boss andhence also the bored member and the said block.
 5. The inventionaccording to claim 4, wherein each eccentric flange has a transverseslot adapted to receive a screwdriver or the like for turning it, andits corresponding bored member is provided around the edge of the holetherein with an annular scale designed to indicate the degree ofadjustment of the eccentric flange and hence also the degree ofadjustment of the block.
 6. The invention of claim 1, wherein saidracking cam carrier is mounted for rotation about an axis and theracking cam is located on the periphery thereof and extends in a helicalpath thereabout, the axis of rotation of said racking cam carrier andsaid racking cam being parallel to the said direction of racking.
 7. Aracking cam mechanism for use in a flat knitting machine comprising: aracking cam carrier having a racking cam mounted thereon and extendingin an oblique direction relative to the direction of racking, saidracking cam including a plurality of discrete opposite shoggingpositions sPaced therealong, the racking cam, at each of said positions,including a control means for varying the form of the cam thereatindependently of the form of the cam at the other shogging position. 8.A racking cam mechanism according to claim 7, said control meanscomprising the construction in which said cam includes a block at eachshogging position, the surface of the block forming the form of a cam atthat position, each block being adjustable relative to the racking camcarrier in a direction generally parallel to the direction of racking ofthe racking cam carrier, each block being the same width, taken in saiddirection of racking, as the racking cam, each such block being formedwith a groove which extends parallel to the edge of the racking cam, abored member accommodated in said groove and including a hole passingtherethrough which locates, with a close working fit, an eccentricflange on a central boss, said eccentric flange being arranged forturning movement adjustably within the racking cam carrier to move thebored member and hence the block in said direction of racking to adjustthe block.
 9. A racking cam mechanism according to claim 8, including ascrew passing through the eccentric flange and central boss andthreadedly engaged with respect to the racking cam carrier such thatwhen screwed inwardly with respect to the racking cam carrier it securesin place the eccentric flange and central boss and hence also the boredmember and the said block, each eccentric flange having a transverseslot adapted to receive a screwdriver of the like for turning it, andits corresponding bored member being provided around the edge of thehole therein with an annular scale designed to indicate the degree ofadjustment of the eccentric flange, and hence also the degree ofadjustment of the block.
 10. The invention of claim 7, wherein saidracking cam carrier is mounted for rotation about an axis and theracking cam is located on the periphery thereof, and extends in ahelical path thereabout, the axis of rotation of said racking camcarrier and said racking cam being parallel to the said direction ofracking.